docs: def build_truncated_gr_mfd(mfd):
      """
      Parses the truncated Gutenberg Richter MFD as a Node
  
      :param mfd:
          MFD as instance of :class:
          `openquake.hazardlib.mfd.truncated_gr.TruncatedGRMFD`
      :returns:
          Instance of :class:`openquake.baselib.node.Node`
      """
      return Node("truncGutenbergRichterMFD",
                  {"aValue": mfd.a_val, "bValue": mfd.b_val,
                   "minMag": mfd.min_mag, "maxMag": mfd.max_mag})